The present invention relates to inhibition of combustion of a surface of a gas producing body, such as a propellant grain or a solid fuel rocket motor or a solid charge for a gas generator.
It is conventional practice to selectively inhibit combustion of solid fuel propellant grains so as to ensure controlled burning of the grain in use. A long-standing problem in this field is to ensure an adequate bond between the propellant and the inhibiting material. The failure of the bond detracts from the control of the burning process, and a substantial failure can result in pressures which will endanger the rocket.
The invention is particularly concerned with inhibition of double base propellants, that is a propellant comprising nitrocellulose and a plasticiser. The latter is usually a liquid nitric ester such as nitroglycerine. The propellant may, however, include additives such as stabilisers, ballistic modifiers, fuels (for example metal particles) and oxidisers (for example ammonium perchlorate).